I'm new to Oracle CRM and I'm trying to use a workflow to email certain user when certain fields are entered. I do not want to email the user if the record is incomplete. The only trigger actions that I have seen were "When New Record is created" and "When record is updated" Is there a way to create a custom trigger, or use the wait option.

Workflow trigger event: *"When Modified record Saved"*
Workflow condition: IfNull(PRE('<Fieldname>'),'Invalid')='Invalid' AND [<Rieldname>] IS NOT NULL (workflow will be triggered only when Fieldname value changes from Blank to some value)